S04. Multiple sclerosis and seizures: An observational study

Abstract

The prevalence of epilepsy (EP) in patients with multiple sclerosis (MS) is three to six times that of the prevalence in the general adult population. The mechanism resulting in an increased seizure risk is unclear. Seizures have been noted to occur prior to or during initial MS attack or relapses while others occur during progressive phases of MS, perhaps suggesting separate etiologies and treatment needs. Some preliminary evidence suggests a higher cortical-subcortical lesion load in MS/EP patients or increased cortical damage with more rapid accumulation of physical and cognitive disability. More recently, MRI studies have shown more severe damage of the temporal lobe in MS/EP patients compared to general MS patients. Demographically, MS/EP patients have been reported as having an earlier age of onset of MS and more rapid progression to disability. All types of seizures have been reported with studies reporting over 60% with partial component. Secondarily generalized seizures have been reported as the most common type. Generally, EP prognosis for MS/EP patients is thought to be good, although some research contradicts this with a high rate of status epilepticus that was often repeated and sometimes resulted in death. Specific treatment parameters and duration of antiepileptic treatment remains undefined. Due to a high rate of status epilepticus, initiation of antiepileptic medication after the first seizure has been proposed. In this single center retrospective chart review we aimed to characterize patients with MS and seizures regarding timing of diagnoses, type of MS, type of seizure, subcortical versus cortical EEG findings, frequency of status epilepticus and seizure freedom. A secondary aim was to determine if there were predicting factors for eventual seizure freedom or status epilepticus. Cases were obtained via DataDirect from the University of Michigan electronic medical record from January 1, 2006 through October, 12, 2016 using EP and MS ICD9 and 10 codes. Thus far, 64 patients met inclusion criteria, 33% male. Average age of MS onset was 34 years of age and average age of seizure onset was 39 years of age. Focal seizures with or without secondary generalization were most common (12% with evidence of temporal etiology). Percent of status epilepticus was 28%. Of patients with EEG data, 52% showed evidence of cortical involvement. In patients with MS and seizures, a high percentage of status epilepticus was noted. More than half of EEGs showed evidence of cortical involvement.